This study investigated (1) the safety and tolerability of HOE901 [30] and [80] in comparison to NPH insulin in IDDM patients receiving basal/bolus insulin treatment (2) to select one of two formulations (ie either [30] or [80] to be investigated in phase III clinical trials and (3) compare efficacy between HOE901 and NPH. The study was completed without adverse events in any of the recruited subjects.